Energy pyramid — Science definition
Defined in 2 courses:
- A diagram of the energy passing through each level over a stated period; unlike a biomass pyramid, it can never invert. (Life Science & Scientific Inquiry)
- A diagram showing how much usable energy is available at each trophic level, with producers forming the wide base. (Life Science: Biology)
Where it is taught
- Energy Pyramids & Transfer Efficiency — Ecosystems, Matter & Energy, Life Science & Scientific Inquiry, Grade 7
- Energy Flow in Ecosystems — Ecosystems & Conservation Decisions, Life Science: Biology, Grade 10
In use
An energy pyramid is the diagram that shows this, with each level's energy drawn to scale, and it is always a pyramid because each level is far smaller than the one below.
Energy Pyramids & Transfer Efficiency
A conventional energy pyramid compares energy transfer over the same area and time, and helps explain limits on supported trophic pathways.
Energy Flow in Ecosystems
Questions using energy pyramid
Problem 1
- Energy per stated boundary and interval
- Only individual names
- An uncalibrated image width
- A genetic allele letter
Answer and explanation
Energy per stated boundary and interval
Define energy units and comparable spatial and time boundaries.
Problem 2
- Producers
- Primary consumers
- Secondary consumers
- Top predators
Answer and explanation
Top predators
Energy is lost at every step, so the top predators at the peak have the least energy available.
Problem 3
Answer and explanation
A pyramid of numbers counts individuals regardless of size, so one very large producer — a single tree — can support many thousands of insects, making the second level wider. Energy is a different quantity: the tree contains far more stored energy than the insects feeding on it, and transfer losses mean the second level always holds less energy than the first. Counting individuals and measuring energy answer different questions, which is why the shapes can differ.
Response criteria
- State a biologically accurate conclusion.
- Show the data, mechanism, or calculation that supports it.
- Include units, conditions, or limits where relevant.
Taught alongside
- trophic position
- transfer efficiency
- biomass
- energy budget
- autotroph
- heterotroph
- trophic level
- ten percent rule
- standing biomass